Computer Animation And Physics : Explaining Universe With Cartoons

A uniformed toy soldier fires a cannon, illustrating how an object goes into orbit; a plane slices a yellow cone into sections to produce the basic geometric figures of circle, ellipse, parabola and hyperbola; a caricature of Galileo calculates the volume of various objects.

These cartoon-like figures are among the unusual computer graphics James Blinn, Ph.D., has created for "The Mechanical Universe," an award-winning video physics class, designed for college students and high school science teachers.

The flat, simple graphics represent a radical departure for Blinn, who has created some extremely sophisticated computer animation. Among his best-known works are the simulated planetary fly-bys for NASA, including the famous visuals of Voyager II's journey through the rings of Saturn.

A tall, genial man with shoulder-length blond hair and a full beard, Blinn talked about his work in his cluttered office at the Jet Propulsion Laboratory in Pasadena.

"I'm more interested in trying to convey ideas than in showing off what great pictures I can make," he explains. "It's easier to make someone understand a lot of these ideas with a simple picture than a complex one, so I use two-dimensional imagery as much as possible and only use three dimensions for concepts that really require it. It's a matter of trying to come up with the simplest possible picture that shows the idea--rather than the most elaborate possible picture."

Over the last four years, Blinn has created more than 7 1/2 hours of computer animation for "The Mechanical Universe"--a staggering amount of work. (A 30-second computer-animated commercial usually requires a production schedule of at least 12 weeks and a budget of $100,000 or more.) The first part of the course--26 half-hour programs--has been shown on public television. The second part, an additional 26 half-hours, will be broadcast starting in early 1987.

The project began six years ago when David Goodstein, Ph.D., redesigned the introductory physics classes at Caltech. Rather than write another textbook, he decided to investigate the possibility of videotaping his lectures. As the project grew in scale, Goodstein received a $5.8-million grant from the Annenberg/CPB Project; the National Science Foundation provided an additional $2.5 million to adapt the course for high school students.

"Computer animation is the technique used in the program for teaching," says Goodstein. "We have historical re-creations and other techniques to give some relief and explain the philosophical and historical context of the issues. But the actual physics is done with Jim's computer animation."

Many of the visuals for programs consist of graphs, formulas and equations that undergo transformations to illustrate specific points. Although the material seems inherently dry, Blinn manages to infuse a quality rarely found in computer animation: humor. When part of a formula is factored out, a human foot descends to crush it; equations are simplified via a chugging device known as "The Derivative Machine." A caricature of physicist Henry Lorenz rides a skateboard past Albert Einstein to demonstrate part of the theory of relativity.

"Part of the goal of the graphics is to make this stuff fun ," says Blinn. "Maybe not uproariously funny all the time, but at least we're having a good time doing it. One of the weaknesses of the 'Cosmos' series was that it took itself too seriously.

"Many of the graphics are designed to be what I would have liked to see before I knew the subject myself," he continues. "When I was studying relativity, a professor would say something, and I'd say, 'Well, I guess I kind of understand that.' Three years later, I'd read a book that explained the point a little better, and two years after that I'd see a diagram and say, ' Now it's perfectly obvious!' I kind of replay those sequences in my mind and try to jump to the clear explanation first."

Much of Blinn's enthusiasm for the "Mechanical Universe" project stems from his childhood experience watching educational television:

"This is kind of a personal mission on my part," he concludes. "I was interested in physics and mathematics, but I didn't have access to a lot of information, growing up in a small town in Michigan. There was something on TV called 'Continental Classroom,' which was a course in physics, math and chemistry. Every morning I was glued to the set at 6 a.m., looking at this stuff and really loving it. I understood maybe half of it, but I thought, 'This is neat stuff, and I want to understand more when I grow up.'

"I feel I'm creating the next generation of this kind of program, so people who don't have ready access to the information can learn that physics is neat, instead of dry and scary."